1. Field of The Invention
The present invention relates to an apparatus for driving a seat test machine for an automobile that utilize one common power means to selectively reciprocate a seat element along a first axis, and to selectively oscillate a twisting member about a rotary axis. More particularly, the present invention includes mechanisms for repeatedly displacing the twisting member along said rotary axis to engage the seat element with a varying gravitational load in order to accurately measure the durability of the car seat.
2. Description of the Prior Art
Ordinarily, an automobile seat deteriorates over time due to its repeated use and the vehicle's vibration from an unevenly surfaced road. The outer skin of the seat can wrinkle and/or stretch, and the interior polyurethane foam can press down and lose its integrity from the cycling of forces applied by the occupant to various parts of the seat. Consequently, a continued wear on the seat can result in deformation and the seat can not function as it was intended.
Typically, a seat test machine uses an actual life-size seat and tests the durability of the seat's interior composition and exterior texture by applying repeated forces on various parts of the seat.
Early tests employed a human occupant. However, this method was limiting due to the extraordinary amount of time involved in observing and supervising. Such lengthy testing sequences not only resulted in inefficiency and unreliable results.
Efforts have been made to eliminate the problems of the earlier method. Among them, two well known approaches are: (1) disclosed in the Japanese Patent, No. 1-51767, "Test Machine for Interior of the Automobile Seat,"; and (2) Patent, No. 4-15893, "Automobile Seat Test Machine for Getting On and Off."
The Japanese Patent No. 1-51767, "Test Machine for Interior of the Automobile Seat" proposes a testing apparatus that uses a reclining seat which includes an operating leveler; a lifting spring mechanism combined with operating mean devices; an hinge coupled to a reclining mechanism; and a lifting spring mechanism controlled by an arm. A rotating arm positioned in the back of seat to resets the reclining seat and lifts the spring mechanism. Each controller is used individually to operate this test machine.
The Japanese Patent, "Automobile Seat Test Machine for Getting On and Off" contains a machine frame with the first movable member for moving in a forward-aft direction; the second movable member for moving in a lateral direction; the third movable element for moving in a vertical direction; a solid testing member for simulating an occupant who is seated and rising from the chair; a rotating drum attached to the solid testing member for applying a rubbing force to various directions against the seat. Furthermore, the machine contains a feature that recognizes road condition including slopes.
Although the first model eliminates the repeated testing of the reclining seat by providing automatic elements, it fails to test the durability and the shock consequence of the exterior texture and the interior polyurethane foam of the seat.
While the second model tests the exterior texture of the seat and its impact on the interior polyurethane foam, it requires assembling a real seat. Moreover, it fails to anticipate the varying weight of occupants. Thus, this testing produces less accuracy and reliability than a test machine equipped to handle variance in weight.
In addition, the second model requires multiple operating devices in order to operate numerous mechanisms involved in the invention, resulting an increase in production cost and as energy use.
Another well known invention is disclosed in U.S. Pat. No. 5,641,917, "Multi-axis Seat Durability Test Machine."
It proposes a multi-axis seat test machine containing: a seat mount and a loading element; a selectively actuable fore-aft displacement mechanism located between the loading element and the seat mount; a selectively acutable lateral displacement located between the loading frame and the seat mount; an engaging member simulating the shape of a human posterior; and, a loading element biasing the engaging member against the seat in a vertical direction with the vertical load.
However, the multi-axis seat test machine still requires the use of a life-size seat. It also requires several shafts to test the interior of the seat; moreover, the machines' complicated assembly produces the same disadvantage of high cost production and energy waste.
Accordingly, it is a goal of the present invention to provide an apparatus for driving a seat test machine for an automobile utilizing one common power means to reciprocate a seat element along a first axis and to oscillate a twisting member about a rotary axis. Moreover, the object of the present invention is to reduce the number of power-driving means in order to reduce production cost and energy use.
Another goal of the present invention is to accurately measure the durability of the car seat by providing mechanisms for repeatedly displacing the twisting member along said rotary axis into impact engagement with the seat element that has varying gravitational load and simulates the different loading condition of the occupant.